Telecommunication system



April 1961 KOSTEN TELECOMMUNICATION SYSTEM 3 Sheets-Sheet 1 Filed June8, 1953 NJE rm 3519. 3 :52

JNVENTOR. IEENDERT Kn T N.

.ATTY.

April 11, 1961 KosTEN 2,979,569

TELECOMMUNICATION SYSTEM Filed June 8, 1953 5 Sheets-Sheet 2 LEENDERTKUSTEN'.

April 11, 1961 KOSTEN TELECOMMUNICATION SYSTEM 3 Sheets-Sheet 5 FiledJune 8, 1953 INVENTOR: LEL'NEERT K5 '1' N.

.AT TY.

2,979,569 Patented Apr. 11, 1961 TELECOMMUNICATION SYSTEM LeendertKosten, The Hague, Netherlands, assignor to Staatsbedrijf derPosterijen, Telegrafie en Telefonie, The Hague, Netherlands Filed June8,1953, Ser. No. 360,304

Claims priority, application Netherlands June 9, 1952 2 Claims. (Cl.179-7) I This invention relates to a telecommunication system containingmnemotechnic means. More particularly, it deals with such a system forrecording variable data regarding the subscribers to said system, suchas for example, recording accumulatively the number of telephone callsand/or their tariff rates by weighted time pulses multiplied accordingto the distance of the call. In the examples to be described, therecording and reading of the metering impulses will only be dealt with,but of course this is not a limitation to the scope of this invention.

It is an object of this invention to produce an eificient, eifective,economic and simple mnemotechnic means for a telecommunication systemand/or an electronic calculator.

Another objectof this invention is to produce a mnemotechnic means inwhich the importance of the counting sequence is not the same in all thedrum cycles, but varies according to a predetermined pattern.

In a given example of an exchange according to this invention, thesubscribers are arranged in groups, e.g. 100, the metering wires of thesubscribers of each group being 7 connected separately and successivelyby means of a multistage timing circuit. Said timing circuit iscontrolled by systems of co-ordinate impulses and the output of saidcircuit controls the supply of metering impulses to a metering device,which carries out the centeral metering and comprises a series adder. Afirst input of said series adder is connected to the output of adistributing device, and an output is connected to a recording head of amagnetic drum. A reading head of said same track on the drum connectedto a second input of said adder in such a way that a loop is formedbetween the output and second input of said adder, which loop isinterrupted between the said recording and reading heads. Impulses maybe taken 01f the drum by the reading head and recorded again via theadder and the recording head, in such a way that if metering impulsesare supplied to the adding device and added to those obtained from thesecond input, therecording head will record on the drum acorrespondingly larger number of impulses. The speed of the impulsespassing around the loop circuit in which the adding device is located isin such a proportion to the speed of the drum that in recording the newnumber of impulses the old number is exactly replaced; however, if nometering impulse is supplied, there is no need for replacing the oldnumber.

-In order to prevent disturbance of the reading system by the recordingsystem, it is generally necessary to introduce a delay unit in the saidloop system.

The code in which the unit calls of the subscribers are recorded isarbitrary and may be either binary, decimal, biquinary, etc. In thegiven example the code is a binary'one and the binary digits arerecorded'on the drum in such a way that the least important ones will beread first. f

j The adding device has anadditionaland third input for timing impulseswhich determine its rhythm.

The timing impulses which control gates in the input of the addingdevicemay ensurethe correct shape for the input impulses, and an impulsegenerator (circuit) supplies all the said timing impulses.

The metering impulses supplied to the metering wires are of apredetermined duration, and they are produced in'the connecting circuit,but their beginning is determined by one or more distributors.

. The drum cycle is coupled with the'i npulse generator cycle, and thecycles of the said distributors so that:

(a) Coincidence is ensured between the scanning of the metering wire ofa subscriber by the timing circuit and the reading of the precedingmetering total of this subscriber from the drum;

p (b) The correct number of impulses is recorded.

Particularly with respect to what-precedes (b), it is observed that, bya suitable timing and delaying of impulsesgoing from the scanningcircuit to the adding device, the importance of the counting can begiven any arbitrary multiple of the unit value. The said delays in theimpulse delivery can depend on a number of distributors, in such a waythat the said importance is not the same in all the drum cycles, butvaries according to a predetermined pattern.

Distributors having different phases with respect to said pattern can beselected according to the zone selected by a connecting circuit in orderthat the metering impulses occur in such phases of'the said pattern thatthey have an efiect on the importance corresponding with the tarifl?chosen.

The above mentioned and other features and objects of this invention andthe manner of attaining them will become more apparent and the inventionitself will be best understood by reference to the following embodimentsof the invention taken in conjunction with the accompanying drawings,wherein:

Fig. 1 is a schematic wiring diagram of an embodiment of thetelecommunication system of this invention show: ing how the number ofcalls made by each subscriber may be accumulatively recorded, and whereportions of the system may be interchanged with the modificationsthereof shown in Figs. 2 and 3;

Fig. 2 is a schematic wiring diagram of a modification of themulti-stage timing circuit of Fig. 1, in particular, the reductionstages thereof;

Fig. 3 is a schematic wiring diagram of a modification of the upperright-hand portion of the circuit of Fig. 1, adapted for the recordationof diiferent tarifi rates according to the different distances of calls;

Fig. 4 is a schematic timing diagram of the cycles of the commutatorsshown in Fig. 3.

' In Fig. 1 the lines of 1000 subscribers are grouped on contact banksof LOO-point line finders OZ, the various connections being led via thecross point connection, such as a diode gating relay cell (described inSnijders copending US. patent application, filed July 25, 1952, now US.Patent No. 2,934,603, issued April 26, 1960, and

assigned to the same assignee as this application) circuits odic patternof synchronizing pulses fed to the leads x1- through x0, y1 through y0,21 through Z0, 15, 16, and

17, is coupled by means of shafts 8, 9, to the magnetic drum MT (whichhas sections arranged in tracks thereon corresponding to eachsubscriber) and to the distributor contacts 11 and 12. The impulsessupplied via conductors 15 and 16 to gates 1P and IP and via conductor17 to the adding device for timing the operation of the latter are alsoadjusted to the general synchronism, the result of which will be setforth below.

During the interval between the first closures of shaft contacts 11 and12 following the closing of contact ha of answering relay BA, relay Aoperates (this operation occurs in the beginning of the said interval);relay B will not be energized until the end'of the interval. Theinterval of 2 seconds between the operations. of relays A and Bcorresponds to a complete revolution of the drum. Thus the distributorcontacts or commutators 11 and 12 insure that the circuit VC of eachsubscriber is connected to the drum MT during one revolutionof the drum,and one revolution only, during which revolution onepaying unit is addedto that particular subscribers account, such as being recorded as animpulse in thesection of the magnetic tape on the drum synchronized tocorrespond with that subscriber according to the last digits of hisnumber as controlled by the multi-stage timing circuit andinputgenerator 1V During this interval, the positive terminal of the batterywill be applied to a wiper of line finder OZ, which is at bank contact67, supposing these digits are the last two digits of the callingsubscribers number. As a result of this, positive potential is appliedto the diode gating relay cell comprising resistors R1 and R2 andrectifiers DI and D2, which are connected, respectively, to conductor 6in the tens co-ordinate group x and conductor 7 in the units co-ordinategroup y. The common point 18 will only become positive at the momentdetermined by these co -ordinates, consequently at moment 67 of theimpulse generator 1V This positive impulse will reach the grid of a tube'5, which becomes conductive in consequence, if the timing co-ordinate Zalso supplies a positive voltage at this moment. The negative impulsethus applied to the common point 19 will reach the first input 7 of theadding device OD via the impulse gate 1P which is periodically openedfor t milliseconds at the highest repetition frequency occurring atpoint 19 under the influence of clock impulses on conductor 15.

The second input 20 of the adding device OD, which forms part of loop13, is fed from the reading head AK via amplifier V1 at momentsdetermined by clock impulses, which cause impulse gate 1P to becomeconductive; in consequence of this the impulses applied to conductor 20are formed or produced so that they cooperate with impulses applied toinput 7 in order to obtain at output 21 the new metering totals, whichfeed via the delay circuit DL and the amplifier V2 the recording headSK.

Thus in loop 13 at conductor'20 there arrives from the reading head AKthe old metering total of the subscriber indicated by the x, y and zco-ordinates and if a metering impulse is received via the reductionstages or multi-stage tuning gates 2, 3 and 4, the increased meter totalis substituted via amplifier V2 and recording head SK on the track ofdrum MT, so that the old total is wiped out.

According to the modification of Fig. 2 of the multistage tuning circuitor reduction stages of Fig. l, the impulse generator 1V produces timingimpulses on 100 outlets xy in the banks of line finders OZ, the wipersconstituting the inputs of the diode gating relay cells. The diodegating relay cells are constituted by rectifiers as D12, D3 andresistors as R1, R2. The relay outlets, multipled in tens, lead topoints 19 through an electronic or vacuum tube 5, as shown in Fig. 1,which feed the adding device in a manner as described above.

The circuit'of Fig. 2 works as follows (supposing the last two digits ofthe calling subscribersnumber are 67):

In the interval determined by generator IV for the metering ofsubscribers 67, the 67 wire bears positive potential and if there arrivma positive metering impulse from the connectingcircuit (which may beconnected to the dashed line conductor 1) to connecting circuit VC, apositive impulse will be applied to the common output of the relay cellsbelonging to the line finders of subscribers; this impulse beingfiltered or gated again by the last timing stage (tube 5) according toFig. 1.

Fig. 3 shows a zone metering circuit or one for recording tariff ratesaccording to the different distances of calls being made, which can beused in an exchange together with the drum circuit shown in Fig. 1 or 2.The dotted line conductor 1 extending to the left in Fig. 3 may beconnected to the dashed line conductor 1 running to the right in Fig. 1or 2. The common output of vacuum tubes 5 can be connected to the dottedline conductor 19 in the lower half of Fig. 3, which leads to theimpulse gate 1P The series counter OD has a first input 7, and a secondone, 20, as well as a timing input 17, just as indicated in Fig. 1. Thedrum and the circuits belonging to it are also equal to those of Fig. l.

The tariii circuit of Fig. 3 comprises the wipers sb, which arecontrolled step by step by magnet SB, and the wipers sa, which arecontrolled step by step by magnet SA. The stepping magnets SA and SB areof the indirect type, i.e. they do not actuate their wipers uponenergization, but only move them to the next contact set on interruptionof the circuit by opening contacts m and S5. The series of contacts foreach of the stepping switches or magnets SA and SB, in which all but thefirst contact of each series are connected together, is provided tode-energize the .circuit of the corresponding magnet when the answeringrelay de-energizes, to close the contacts ha and ba' to'return thestepping magnets SA and SB ot their home positions. Connected to each ofthe wipers operating over these series of contacts are normally closedswitches sa' and sb', respectively, to break the circuit to therespective stepping magnets SA and SB, because these magnets only stepwhen their circuits are broken.

The tariff zone meter TZO has an output relay T and is connected to fivecommutators A-E, mounted on one shaft connected to a gear box GB, whichgear box is driven by a shaft 8, 9 or iii of Fig. l, and each commutatoris divided into equal parts i, Ii, HI, and TV. The opening andclosing oithe contacts is illustrated by Fig. 3 in conjunction with Fig. 4.

Normally the wipers sa and sb are on their contacts 1. After thecompletion of a call, the metering wire 1 of the calling subscriber isconnected via the wiper of line finder OZ (Fig. 1) to the positiveterminal of the battery via contact 2 (Fig. 3), this connection beingestablished in such periods as correspond with the tariff conditions.

These conditions involve a single impulse on completion of a call, animpulse of a value of 1, 4 or 8 according to the zone at the end of afree period occurring about 5 to 10 seconds after a call connection hasbeen made but before the tariff rate starts, and single impulsesoccurring every 60, 30 or 10 seconds according to the relevant zone.

The relay T will be energized via those contacts z z z that are closedaccording to the zone after the completion of the call, z correspondingto the most expensive zone, which will be clear from the connection oftariff contacts to (i.e. contacts 1" through 12" in Figure 3).

The zone meter works as follows: When a call is established, one of thecontacts z z or 2 is closed by its corresponding zoning relay ZA, ZB, orZC, respectively, as well as contact bu (similar to contact ha in Fig.1).

This closing may take place in anyof the intervals LIV of Fig. 4,according to the instantaneous position of the commutators A through Ifit occurs in the intervals or positions 1101' IV, the magnet SA (shownas a square) is energized, and the'wipers sa step to contacts 2, whenthe circuit is again broken by the commutator passingto the position 111or I. Via the contact 2 and segment I or HI of commutator B, the magnetSA is energized, so that the wipers make a step after the interruptionof this energization during the further rotation of commutator B. Itwill be apparent on inspection that the first step of magnet SA willtake place at the most 2 /2 secs. (=2 1 A secs.) after the closure ofcontact ba (which occurs at arbitrary moments with respect to thecommutator phase) and at its earliest possible time immediately afterthe closure of contact ba. If contingent differences between theenergization and release times of magnet SA are neglected, it will beseen that the wipers will be at contact 2 for about 1% sec. During thisinterval, the relay T will be energized in a circuit running from theground at contact 2, through wiper sa to one of the zone contacts z zand finally to relay winding T to the battery. Contact t will cause therecording of a first charge dependent on the zone.

After three steps, the switch SA will be under the control of commutatorC and, consequently, stop on each of the contacts 3, 4 and 5. At thelast mentioned contact 5, the relay T will be energized again. Theoriginal circuit was interrupted when the wipers left contact set 2.This second operation will be under the control of commutator C (if 2,,had been closed for the lowest zone), or under the control of commutatorE (if instead z has been closed for the highest zone), or under thecontrol of commutator D (in the remaining case of contact 2 beingclosed). It should be observed that the circuit for closing each of'thez-contacts by their corresponding ZA- ZB and ZC relays in thetariif-zone repeater has not been shown, in that when a calledsubscriber answers, one of these relays operates depending upon the zonein which that call is located with reference to the calling subscriber.

The values attributed to the closureof each of these contacts areindicated in Fig. 4 by means of Arabic numbers right above the contactdesignations in Roman numbers, which correspond to the numbers at thesegments or trafiic contacts 1" through 12" or tc in Fig. 3.. Thisimportance or weighted value for different pulses influences theoperating periods of relay T. The last operating period occurs 5 secondsafter the wipers sa reach contact set 5 (in the case of energization viacommutator C), after 2 /2 seconds (in the case of energization viacommutator D), and practically immediately (in the case of energizationvia commutator E); the duration of the operation of relay T is regularlyabout 1% seconds. Irrespective of whether the energization is determinedby C, D, or E there will always be aperiod in the energizing interval ofthe relay T at which a calling line'finds its metering contact in thebank of line finder OZ connected via the timing circuit of Fig. 1 to thedrum and the adding device, as in this case the period of the timingcircuit amounts to 1% seconds, during which interval all the subscriberslines the tariff-zone repeater is provided for are successivelyconnected to the adding device and to the drum.

Of the commutators C, D and E, the one controlling the T-relay,,via oneof the actuated zone contacts 2,, z or 2 controls at the same time oneof the impulse filters or gates IP;,, IP, and 1P as a result of whichthe metering impulse can pass from contact t via the timing circuit(Fig. 1) to the impulse gate 1P and to the combination of impulse gatesIP;,, IP,,, and 1P and delay circuits D D which ends in conductor 7.

The working of this combination is as follows: Supposing one of the zonecontacts z z or 2,, has been closed (after completion of the call),relay T will operate in one of the periods determined by the commutatorsC, D, or E. During the period of energization of relay T, a meteringimpulse will be led from contact t via the timing circuit (during theperiod or section of tape on 6 the magnetic drum MT which under thesynchronism of themulti-stage timing circuit and input generator 1V (seeFig. 1) corresponds to the calling subscribers number); it will arriveat gate IP, (which is controlled in the same way as indicated withregard to Fig. 1) and be passed without delay to gate 1P with a delay ofZn milliseconds in the delay circuit D to gate IP, and with a delay of3n milliseconds in the delay circuit D to gate 1P the quantity n will bespecified below.

With regard to the operating periods of relay T, which coincide,successively, with the periods that impulse gates 1P 1P and 1P areopened, these delays can be neglected.

If contact 2,, is closed for a call in the lowest zone, relay T willoperate under the control of commutator C; the metering impulse willarrive at 1P in the interval that this gate is opened by the controlimpulse originating from commutator C. If contact z is closed for a callin the highest zone, relay T will operate under the control ofcommutator E and the metering impulse will arriveat impulse gate 1P inthe interval that this gate is opened by the control impulse originatingfrom commutator E. The impulses arriving at the other gates will findthese gates closed. The period of revolution of the drum for scanning acomplete revolution of a tape thereon is in this case 1% seconds.

It results from the above that with each revolution of the drum (whichone is irrelevant of course) a metering impulse for the same subscriberalways arriva on the same part of the drum'track, but with a delay of Znmilliseconds for calls in the intermediate zone, of 3n milliseconds forcalls in the highestzone, and instantaneously or zero milliseconds forcalls in the lowest zone.

As has been described before the digits of the lowest 7 importance orweighted value are recorded first on the part of the drum destined forthe meteringtotal of a given subscriber. The interval of n millisecondsis the lapse of time'between digits of successive order. Consequently,in n milliseconds the value of an impulse to be recorded will be doubled(recording is done in the binary system), in 2n milliseconds it will bemultiplied by 4 (its logarithm will be doubled) in 3n milliseconds itslog- -mutator C via contact'5', wiper sa and magnet SA is interrupted bycommutator C. From now on magnet SB is energized every 5 seconds-in acircuit running from commutator C via wiper sa on contact 6, magnet SBto the battery.

After the first interruption of this current by commuator C, wipers .917will be at contacts 2, ten seconds later at contact 3, etc. The bankcontacts to are multipled in pairs for the highest zone, in groups ofsix for the intermediate zone and in dozens for the lowest zone. As aresult of this, relay T delivers a single impulse (via impulse gate 1Pto the adding device, notably every 10 seconds for the highest zone,every 30 seconds for the intermediate zone and every minute for thelowest zone. The tc tank contacts are arranged in circles and in thisway metering goes on uninterruptedly.

Recapitulating it can be said that metering occurs according to thefollowing time division:

( 1) At moment 0: for zone. a, b and 0 zone contacts,

z 2,, or z,, and b, are closed;

(2) From 02 /2 seconds to 1%-3% seconds: wiper szz is on contact 2 andrelay T operates to send a single metering pulse through the circuit ofFig. l, and then via intervals I or III and impulse gate IP; to theadding device OD;

(3) From 1 ,44 4 seconds to 6%8% seconds: wiper awe-nae sa is on contact3, during which time nothing happens and free time is given to thesubscriber;

(4) From 6%8% seconds mills-13% seconds: wiper sa is on contact 4,during which time nothing happens and free time is given to thesubscriber; and

() From IPA-13% seconds to 16 /4-18% seconds: wiper sa is on contact 5,when a metering impulse is sent out by relay T- to the adding device OD.

If the plays in this survey are too large, a pattern of drum cycleshaving a finer division can be used, which requires more apparatus ascommutators, etc.

Thus, in the circuit according to Fig. 3 when a subscriber makes a call,he is connected to the drum MT during the whole duration of the call,upon which drum is recorded first a given number of paying units andthen additional paying units at equal intervals of time thereafter, theweighted values or" which unitdepend upon the distance of the call,controlled by the zoning relays ZA, ZB, and ZC.

In order to make the system completely operable, the tariff records inthe different sections of the drum MT assigned to diiferent subscribersor their numbers, must be able to read from the drum at the billingperiod to determine the bill or tariif to be charged to each subscriberfor their service. Thus, a reading out device ROD is shown in a box in.Fig. l which must be connected both to the different subscribers numbersentering the synchronizing device and input generator 1V and to the loopcircuit 13, which reading out device ROD may also include means forconverting the pulses'read from the drum corresponding to eachsubscriber, into printed words on cards or bills, with the correspondingsubscribers number also printed thereon with the total amount he shouldbe charged for his service.

While I have illustrated and described what I regard to be the preferredembodiment of my invention, nevertheless it will be understood that suchis merely exemplary and that numerous modifications and rearrangementsmay be made therein without departing from the essence of the invention,I claim:

1 In a telecommunication system having a plurality of subscribers, eachsubscriber having: a metering wire, con' necting circuits for connectingany two of said subscribers in said system, an exchange to which atleast a group of subscribers are connected, and a metering circuit insaid exchange for valuing calls between two subscribers accord-.

ing to their duration and tariff zone, said metering circuit comprising:a tariif circuit connected to each connecting circuit of a callingsubscriber of said exchange including means for producing time meteredimpulses on the metering wire of said calling subscriber, a zone markingmeans connected to said traflic circuit'and controlled by the calledsubscriber for indicating the zone corresponding to said call, areduction circuit connected to said metering wires; an impulse generatorconnected to said reduction circuit to successivelyscan said meteringwires for-metered impulses, a distributor connected to and controlled bysaid impulse generatorfor controlling said metered impulses fromsaidtrafiic circuit in difierent time intervals controlled by said zonemarking means, a rotating magnetic drum divided into sectionscorresponding to each subscriber of said exchange for recordingcumulative totals of said metered impulses, said drum being connected toand synchronized with said impulsegenerator and said distributor, eachsection of said drum being divided into equal parts corresponding to thedifferent z'one'relatecltime intervals produced by said distributor; agating means connected to and controlled by said impulse gcnerator,-said distributor, and said reduction circuit for passingmetered-impulses for recordation on said drum in said zone related partsselected by said distributor in said sections corresponding to eachsubscriber, a recorder for recording said metered impulses on said drum,a reader spaced in advance of said recorder for reading the impulsesalready recorded on said drum, an adder connected between said readerand said recorder and to said gating means for adding the gated meteredimpulses to those read from the corresponding zone related part of eachsection on said drum, and a delay device connected between said adderand said recorder for compensating for the time the drum takes to rotatethrough said space fromsaid reader to said recorder to insurerecordation of said cumulative metered impulses in the correspondingsubscribers zone related section part.

2. A system according to claim 1 wherein said gating meanscompiises aplurality of gating circuits each having an input'and being connected inparallel between said reduction circuit and said adder, and additionaldelay de vices between the inputs of adjacent ones of said gatingcircuits which delay devices correspond to zone related time parts onearth subscribers section on said drum.

References Cited in the file of this patent UNITED STATES PATENTS Wrightetal. Dec. 23,

